org.ldp4j.server.data.impl.CoreRuntimeDelegate.java Source code

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Here is the source code for org.ldp4j.server.data.impl.CoreRuntimeDelegate.java

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/**
 * #-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=#
 *   This file is part of the LDP4j Project:
 *     http://www.ldp4j.org/
 *
 *   Center for Open Middleware
 *     http://www.centeropenmiddleware.com/
 * #-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=#
 *   Copyright (C) 2014-2016 Center for Open Middleware.
 * #-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=#
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *             http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 * #-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=#
 *   Artifact    : org.ldp4j.framework:ldp4j-server-core:0.2.1
 *   Bundle      : ldp4j-server-core-0.2.1.jar
 * #-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=#
 */
package org.ldp4j.server.data.impl;

import java.util.Collections;
import java.util.List;
import java.util.ServiceLoader;
import java.util.Set;

import javax.ws.rs.core.MediaType;

import org.ldp4j.server.data.spi.MediaTypeProvider;
import org.ldp4j.server.data.spi.RuntimeDelegate;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.collect.Lists;
import com.google.common.collect.Sets;

public class CoreRuntimeDelegate extends RuntimeDelegate {

    private static final Logger LOGGER = LoggerFactory.getLogger(CoreRuntimeDelegate.class);

    private final List<MediaTypeProvider> providers;
    private final Set<MediaType> mediaTypes;

    public CoreRuntimeDelegate() {
        this.mediaTypes = Sets.newLinkedHashSet();
        this.providers = Lists.newCopyOnWriteArrayList();
        populateMediaTypeProviders();
    }

    private void populateMediaTypeProviders() {
        ServiceLoader<MediaTypeProvider> loader = ServiceLoader.load(MediaTypeProvider.class);
        for (MediaTypeProvider provider : loader) {
            addMediaTypeProvider(provider);
        }
    }

    private void addMediaTypeProvider(MediaTypeProvider provider) {
        this.providers.add(provider);
        this.mediaTypes.addAll(provider.supportedMediaTypes());
        if (LOGGER.isDebugEnabled()) {
            LOGGER.debug("Registered media type provider '" + provider.getClass().getCanonicalName()
                    + "'. Extended media type support for: " + provider.supportedMediaTypes());
        }
    }

    @Override
    public Set<MediaType> getSupportedMediaTypes() {
        return Collections.unmodifiableSet(this.mediaTypes);
    }

    @Override
    public MediaTypeProvider getMediaTypeProvider(MediaType mediaType) {
        for (MediaTypeProvider candidate : this.providers) {
            if (candidate.isSupported(mediaType)) {
                return candidate;
            }
        }
        return null;
    }

    @Override
    public void registerMediaTypeProvider(MediaTypeProvider provider) {
        if (provider != null) {
            addMediaTypeProvider(provider);
        }
    }

}